Nurses tend to a child with cancer at Damascus Children's Hospital in Damascus, Syria, March 16, 2017. REUTERS/Omar Sanadiki SEARCH "CANCER CHILDREN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Nurses tend to a child with cancer at Damascus Children's Hospital in Damascus, Syria, March 16, 2017. REUTERS/Omar Sanadiki SEARCH "CANCER CHILDREN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.